Effect of hot‐rolling conditions on the tensile properties of multiphase steels exhibiting a TRIP effect

TRIP‐assisted multiphase steels have been thoroughly studied in the cold‐rolled and annealed state. The effects of hot‐rolling conditions on these steels are much less studied even though these are of major importance for industrial practice. This study was carried out in order to understand the effect of the hot deformation of austenite on the tensile properties of TRIP‐assisted multiphase steels. Two different compositions and microstructures are investigated. The first one is a low‐carbon steel (mass content of 0.15 %) with a microstructure consisting of an intercritical ferritic matrix, bainite and retained austenite. The second one is a medium‐carbon steel (mass content of 0.4 %) that consists of bainite and retained austenite. Both steels were deformed to various strain levels below the non‐recrystallisation temperature of austenite. The medium carbon steel was deformed in the fully austenitic temperature range whereas the low‐carbon steel was deformed in the intercritical temperature range. In both cases, the prior hot deformation of austenite brings about a large enhancement of the work‐hardening capabilities. In the case of the medium‐carbon steel, this effect can be attributed to a much larger TRIP effect taking place during straining. In the case of the low‐carbon steel, the improvement of the work‐hardening behaviour was attributed to an Interaction between the martensitic transformation and the dislocations already present within the surrounding ferrite matrix.     

The effect of R 15.7/HO, an anti-CD18 antibody, on the late airway response and airway hyperresponsiveness in an allergic rabbit model

1. The effects of a mouse (IgG1 fraction) anti-CD 18 neutralizing antibody (R15.7) on allergen-induced late airway response (LAR), airway hyperresponsiveness (AHR) and cellular recruitment were investigated in an allergic rabbit model. 2. Litter-matched NZW rabbits immunized within 24 h of birth with Alternaria tenuis (i.p.) and subsequently exposed to the allergen (i.p.) for the first 3 months of life were challenged with inhaled allergen as adult rabbits. Lung function in terms of dynamic compliance (Cdyn; ml cmH2O-1) and total lung resistance (RL; cmH2O-1 s-1) was monitored for 6 h following the allergen challenge. On day 16, separate groups of rabbits were pretreated with either control antibody (a non-binding mouse IgG1, 1 mg kg-1, i.v.) or R15.7 (1 mg kg-1, i.v.) and 1 h later all were challenged with Alternaria tenuis and lung function monitored thereafter. Airway responsiveness to inhaled histamine was assessed by measuring RL and Cdyn 24 h before and after allergen challenge and bronchoalveolar lavage (BAL) was also performed 24 h before and after allergen challenge. 3. Pretreatment of rabbits with the control antibody had no effect on the LAR as measured by AUC (Cdyn, 0-6 h). However, the magnitude of the LAR following treatment with R15.7 was significantly reduced when compared to LAR demonstrated on 1st challenge (P < 0.001) or to that of the control group on both challenges (P < 0.01). 4. In control antibody pretreated rabbits allergen induced a significant 3.4 fold reduction in the PC50 response to inhaled histamine in terms of RL changes (P < 0.05) and a significant 2.1 fold reduction in PC35 response to inhaled histamine in terms of Cdyn changes (P < 0.05). However, in anti-CD 18 antibody pretreated rabbits there was no significant change in responsiveness to histamine 24 h following allergen, as assessed by either RL PC50 or Cdyn PC35. 5. Allergen challenge induced a significant increase in eosinophil and neutrophil numbers (P < 0.05) in rabbits pre-treated with control antibody, whereas treatment with R15.7 significantly inhibited this increase in the numbers of both cell types. 6. This study demonstrates that the neutralization of CD-18 molecules reduces allergen-induced infiltration of both eosinophils and neutrophils into the airways and abolishes the accompanying LAR and AHR. These results provide evidence to support a role for CD-18 adhesion molecules in the transmigration of inflammatory cells into airways.     

Integrity and the quality of information: Part 2

In the information systems security community, the process of maintaining integrity has long been understood as the implementation of a set of safeguards against unauthorized modification of information. This point of view, which comes from the military world, is now seriously challenged: integrity could simply be seen as the ability to maintain an acceptable level of quality of information. This concludes the articles which discuss the general concept of quality and give an overview of the various quality dimensions of information.     

Comparative analysis of active and passive solar heating systems with transparent insulation

The objective of this research is to achieve a high solar fraction in social housing, for which investment costs are strictly limited. Six houses have been built in the east of France: two with active (solar collectors) and four with passive (Trombe walls) solar heating systems. Two types of transparent covers are compared: a capillary structure and a simpler polycarbonate plate. The project was monitored during 1 year. Experimental measurements as well as simulation results are presented in this article. The use of simulation allowed a comparison of the various systems on a common basis, i.e., minimizing the effect of different occupants behaviour. Compared to the less expensive cover, transparent insulation increased the productivity of the air collectors 25% and doubled the gain of the Trombe wall. Thanks to passive or active controls, the thermal comfort was not reduced by the solar systems in summer nor in mid-season.     

Excess prevalence of fasting and postmethionine-loading hyperhomocysteinemia in stable renal transplant recipients

Hyperhomocysteinemia, either fasting or after methionine loading, may contribute to the increased incidence of cardiovascular disease events experienced by renal transplant recipients. Limited data are available on fasting homocysteine (Hcy) levels, and none on postmethionine-loading Hcy levels, in these patients. We assessed the prevalence and potential determinants of fasting and postmethionine-loading hyperhomocysteinemia in 29 stable renal transplant recipients and 58 age- and sex-matched, population-based controls free of renal disease with serum creatinine levels of 1.5 mg/dL or less. Total (t) plasma Hcy was determined fasting and 2 hours after methionine loading, along with fasting determinations of the B-vitamin cofactors/substrates for Hcy metabolism, ie, pyridoxal 5'-phosphate, B-12, and folate and serum creatinine. Geometric mean fasting (18.1 versus 9.8 microM, P < .001) and postmethionine-loading increase (22.0 versus 15.2, P = .001) in tHcy levels were significantly greater in the renal transplant recipients, as were the prevalence odds (with 95% confidence intervals) for fasting [14.8 (3.4-64.7)], postmethionine loading [6.9 (1.5-32.8)], combined fasting and postmethionine-loading [18.0 (2.3-142.1)] hyperhomocysteinemia, and inadequate circulating folate [4.2 (1.1-16.5)] or pyridoxal 5'-phosphate [3.2 (0.9-11.0) status. Correlation analyses suggested important potential relationships between creatinine and both fasting (+0.64, P < .001) and postmethionine-load increase (+0.38, P = .045) in tHcy, folate and fasting (-0.41, P = .025) tHcy, and pyridoxal 5'-phosphate and postmethionine-loading increase (-0.33, P = .091) in tHcy. We conclude that there is an excess prevalence of fasting and postmethionine-loading hyperhomocysteinemia in stable renal transplant recipients. Renal function is related to both fasting and postmethionine loading-hyperhomocysteinemia, inadequate folate status is associated with fasting hyperhomocysteinemia, and inadequate vitamin B-6 status may be related to postmethionine-loading hyperhomocysteinemia in this patient population.     

Elastic and Creep Properties of Alumina-Based Single Fibers

Young's moduli, creep properties, and time to failure under steady loads were measured for two types of alumina-based single fibers. Microstructural changes during deformation (grain growth and cavitation) have been analyzed. Experimental dispersion has been correlated to fiber diameter scatter. It has been shown that the fibers' behavior is similar to the behavior of bulk materials. Addition of zirconia particles slightly improved the creep and rupture properties of the materials.     

Securing the future for nylon

Since its introduction over 50 years ago, nylon has proved a highly useful fibre in the clothing industry. In this article, Les Jacques looks at developments which have been made in nylon fibres to ensure its continuing importance in the industry.     

INCIDENCE OF INDIGENOUS MICROBIAL FLORA FROM UTENSILS AND SURROUNDING AIR IN TRADITIONAL FRENCH CIDER MAKING

Lactic acid bacteria and yeasts were numerated, isolated and identified from two ciders obtained from similar raw materials used under different conditions. One cider was produced in a cellar of a traditional producer while the second one was produced under laboratory conditions. In both ciders alcoholic fermentation was achieved mainly by Saccharomyces cerevisiae. In the traditional cider, among the lactic acid bacteria (LAB) the species Leuconostoc oenos was predominant and malolactic conversion was observed. By contrast no development of LAB occurred in the second cider and therefore malolactic conversion was not achieved .